Molecular Genetics Flashcards
How is DNA organised inside the nucleus
Each DNA molecule consists of 2 parallel strands twisted around each other to form a double helix structure .
A molecule of DNA is wrapped around proteins to form a single chromatin thread.
Definition of DNA
A molecule that carries genetic information.
Made up of nucleotides
What a nucleotide is made up of
A sugar molecule
A phosphate group
A nitrogen containing base
Definition of a gene
A sequence of DNA that codes for polypeptide.
How are proteins made using DNA as examples
DNA is transcribed into MRNA through transcription in the nucleus.The MRNA is the. Translated into polypeptides through translation in the cytoplasm.
Differences between DNA and RNA
DNA’s sugar unit is deoxyribose , nitrogen-containing bases are A , T , C ,G.Ratio is fixed at 1:1 .Large insoluble molecule .Permanent molecule in the nucleus.
RNA’s sugar unit is ribose, nitrogen bases are A,U,G,C.No fixed ratio between nitrogen bases.Small soluble molecule and is a temporary molecule that’s is made when needed.
Definition of genetic engineering
The manipulation of an organism’s genetic material
The process of gene engineering
1.Isolate the desired gene by cutting the gene using a restriction enzyme.
2Use the same restriction enzyme to cut the vector DNA .Insert the cut gene into the vector DNA using ligand , an enzyme to join the 2 molecule together.
Insert the recombinant plasmids into the bacteria with heat or electric-shock the cells.
What is a vector molecule
A DNA molecule , virus or bacterium that is used to transfer gene-if-interest into another organism.
Large scale fermenters
Use to culture large amount of transgenic bacteria by keeping ideal conditions for bacteria to grow such as pH , aeration system , nutrients , temperature.
Selective breeding
Organism involved must be closely related or same species.Possible for defective genes to be passed to the offspring.Slow process that involves several generations.Less efficient as organism grows more slowly and may requires more food.
Genetic engineering
Genes from an organism can be inserted into non-related or different species.Selection of genes before transfer eliminates risk of transferring a defective gene.A process that rapidly reproduce individual cells in a small container in a laboratory.More efficient as transgenic organisms grow faster and may require less food.
Advantages of genetic engineering
Low cost production of medicines , production of crops in extreme conditions, development of pesticides -resistant crops, development of foods designed to meet specific nutrition goals.
Human insulin becomes affordable
Disadvantages of genetic engineering
Economic hazards
-If prices of modified crops are not regulated , poorer farmers may not have financial capacity to benefit from this technology while richer farmers continue to get richer through this technology.
Health hazards
-Gene may be accidentally incorporated into bacteria that causes human diseases or may cause allergic reacreaction in huamns
Social and ethical hazards
- May led to class distinctions
Some religions do not approve to alter natural genetic makeup-up of organisms.
